If abnormal lines, dots, and spots disappear when you change the screen content, the issue may be related to the TV input signal or display aspect ratio.
To troubleshoot, check the TV aspect ratio settings, verify the antenna cable connection and signal input settings, replace the HDMI cable, and change the input signal to a different device.
Additionally, perform a Picture Test.
If problems persist even after a Picture Test, please contact LG Support for further assistance.
Try this
Set the aspect ratio to 16:9.
Navigating to Aspect Ratio Settings
[~ webOS 5.0 TV released before 2020]: Remote control Settings [
Steps for changing the Aspect Ratio on webOS24, 25 TVs (released in 2024)
1. Press the Settings[] button on the remote control. Select the All Settings[
] icon from the quick menu.
2. Select the [Picture] tab, then [Aspect Ratio].
3. Choose [User Selection].
4. Select the ratio [16:9].
Check the antenna connection
Inspect the antenna cable and ensure that it is securely connected.
Make sure the TV is receiving input signal.
Check the HDMI cable connection between devices
1. Inspect the HDMI cable connection and make sure the TV is receiving HDMI signal input.
To check for cable or signal input issues, try connecting another HDMI cable.
2. Check the HDMI port on the back of the set-top box.
3. Ensure the HDMI cable is securely connected to the set-top box (external device).
Picture Test, also called Screen Self-Diagnosis, is a feature that checks for display issues on the TV.
If no issues are found during the Picture Test, but display issues continue, there may be problems with signals sent to the TV from the set-top box or via the internet.
If that is the case, you may need to contact your service provider or the internet provider.
Note that Picture Test cannot be performed if the on-screen menu does not appear using the TV remote control settings button.
For further assistance, please contact LG Electronics Support.
How to navigate to Picture Test / Screen Self-Diagnosis on your webOS TV
[OLED TVs][webOS 6.0 ~ 23] released between 2021 & 2023: Remote control Settings [
[QNED, NANO Cell, Ultra HD, LED TVs] [webOS 6.0~ webOS 25] released after 2021: Remote control Settings [
[TVs][webOS 5.0] released in 2020: Remote control Settings[
[TVs] released before 2019: Remote control Settings [
How to perform Picture Test on webOS24, 25 TVs (released in 2024)
1. Press the remote control Settings[] button. Select All Settings [
] from the quick menu.
2. Select the [Support tab], then [Screen Self-diagnosis].
3. After selecting [Screen Self-diagnosis], a test screen will appear.
If no issues are found, the external device and its connection may be the problem.
However, if you notice any issues on the test screen, please contact LG Electronics Support.
You can enjoy a clearer image when you connect a device that supports HDMI Ultra HD Deep Color.
However, if the connected device does not support the feature, screen abnormalities may occur.
In that case, the TV’s HDMI ULTRA HD Deep Color setting needs to be turned OFF.
Changing HDMI Ultra HD Deep Color setting on your webOSTV
[ ~ webOS 5.0] TVs released before 2020 : [Settings] → [All Settings] → [Additional Settings] →[HDMI Ultra HD Deep Color]
How to turn off HDMI Ultra HD Deep Color
1. Press the remote control Settings [] button, then select the All Settings [
] icon from the quick menu.
2. Select the [General] tab, then [External Devices].
3. Select [HDMI Settings]. Choose the connected input and turn it OFF.
* If issues persist, please contact LG Electronics Support for assistance.
This guide was created for all models, so the images or content may be different from your product.
